jdbc開始失敗

Question

訪問Web服務時，我會隨機收到此錯誤。它很難復制，並且一旦刷新它，一切都會按預期運行。

Caused by: org.hibernate.exception.JDBCConnectionException: could not execute query
        at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:97)
        at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:66)
        at org.hibernate.loader.Loader.doList(Loader.java:2235)
        at org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2129)
        at org.hibernate.loader.Loader.list(Loader.java:2124)
        at org.hibernate.loader.criteria.CriteriaLoader.list(CriteriaLoader.java:118)
        at org.hibernate.impl.SessionImpl.list(SessionImpl.java:1597)
        at org.hibernate.impl.CriteriaImpl.list(CriteriaImpl.java:306)
        at edu.asd.myproj.hibernate.adapter.CriteriaAdapter.list(CriteriaAdapter.java:380)
        at edu.asd.myproj.DaoHibernateImpl.findByCriteria(DaoHibernateImpl.java:778)
        at edu.asd.myproj.DaoHibernateImpl.findByCriteria(DaoHibernateImpl.java:765)
        at edu.asd.myproj.DaoHibernateImpl.findByProperty(DaoHibernateImpl.java:361)
        at edu.asd.myproj.ProfilesDaoImpl.count(ProfilesDaoImpl.java:81)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
        at java.lang.reflect.Method.invoke(Method.java:597)
        at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:307)
        at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:182)
        at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:149)
        at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:106)
        at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:171)
        at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:204)
        at $Proxy27.count(Unknown Source)
        at edu.asd.myproj.ResourceProfileLoaderNew.loadProfiles(ResourceProfileLoaderNew.java:66)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
        at java.lang.reflect.Method.invoke(Method.java:597)
        at org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor$LifecycleElement.invoke(InitDestroyAnnotationBeanPostProcessor.java:297)
        at org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor$LifecycleMetadata.invokeInitMethods(InitDestroyAnnotationBeanPostProcessor.java:250)
        at org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor.postProcessBeforeInitialization(InitDestroyAnnotationBeanPostProcessor.java:144)
        ... 50 more
    Caused by: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: The last packet successfully received from the server was44323 seconds ago.The last packet sent successfully to the server was 44323 seconds ago, which  is longer than the server configured value of 'wait_timeout'. You should consider either expiring and/or testing connection validity before use in your application, increasing the server configured values for client timeouts, or using the Connector/J connection property 'autoReconnect=true' to avoid this problem.
        at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
        at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
        at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
        at java.lang.reflect.Constructor.newInstance(Constructor.java:513)
        at com.mysql.jdbc.Util.handleNewInstance(Util.java:406)
        at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1074)
        at com.mysql.jdbc.MysqlIO.send(MysqlIO.java:3246)
        at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1917)
        at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2060)
        at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2542)
        at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:1734)
        at com.mysql.jdbc.PreparedStatement.executeQuery(PreparedStatement.java:1885)
        at org.apache.commons.dbcp.DelegatingPreparedStatement.executeQuery(DelegatingPreparedStatement.java:93)
        at org.hibernate.jdbc.AbstractBatcher.getResultSet(AbstractBatcher.java:208)
        at org.hibernate.loader.Loader.getResultSet(Loader.java:1812)
        at org.hibernate.loader.Loader.doQuery(Loader.java:697)
        at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:259)
        at org.hibernate.loader.Loader.doList(Loader.java:2232)
        ... 79 more
    Caused by: java.net.SocketException: Broken pipe
        at java.net.SocketOutputStream.socketWrite0(Native Method)
        at java.net.SocketOutputStream.socketWrite(SocketOutputStream.java:92)
        at java.net.SocketOutputStream.write(SocketOutputStream.java:136)
        at java.io.BufferedOutputStream.flushBuffer(BufferedOutputStream.java:65)
        at java.io.BufferedOutputStream.flush(BufferedOutputStream.java:123)
        at com.mysql.jdbc.MysqlIO.send(MysqlIO.java:3227)
        ... 90 more

這是我的hibernate.properties文件

# Turn on for SQL debugging
hibernate.show_sql=true

# Generate schema?
hibernate.hbm2ddl.auto=validate

#============================================================
# C3P0 connection pool configuration
#============================================================
#changed to default values 
c3p0.acquireIncrement=hibernate.c3p0.acquire_increment
c3p0.idleConnectionTestPeriod=hibernate.c3p0.idle_test_period
c3p0.initialPoolSize=10
c3p0.maxIdleTime=hibernate.c3p0.timeout
c3p0.maxPoolSize=hibernate.c3p0.max_size
c3p0.maxStatements=hibernate.c3p0.max_statements
c3p0.minPoolSize=hibernate.c3p0.min_size   
c3p0.testConnectionsOnCheckout=hibernate.c3p0.validate

錯誤會隨機出現一次，並且需要很長時間才能重新出現，一旦刷新就會消失。

Answer 1

請發送完整的異常堆棧跟蹤，以進一步了解讀者。

通常在DB Connection陳舊時發生此異常。

過時的意思是 ：服務器終止了連接，但池仍然認為該連接處於活動狀態。 您需要在連接中配置連接測試。 對於C3P0這種方法，您必須使用以下配置：

c3p0.testConnectionOnCheckin = true
testConnectionOnCheckout= true

對於更多檢查，請增加結帳超時，如下所示：

c3p0.checkoutTimeout = 0

並在C3P0測試另一個測試選項，例如：

• connectionTesterClassName
• idleConnectionTestPeriod
• automaticTestTable
• preferredTestQuery

測試的另一種方法是編寫示例代碼並通過JDBC pure代碼連接到數據庫（通過DriverManager和Connection等）。